Several studies have shown racial and ethnic disparities in the quality of care provided by neonatal intensive care units (NICUs) to very low-birth-weight (VLBW; 1500g) infants. However, no routine comprehensive assessment of this problem exists, depriving health care providers of a roadmap to improvement. Feedback of information about quality has been used successfully to improve care and outcomes for VLBW infants and may be applied to reduce or eliminate disparity in outcomes. We therefore propose to study racial and ethnic differences in quality of care provided by NICUs to VLBW infants and to translate our findings into a web-based real-time disparity dashboard. Employing unique existing resources and linked data sets not available elsewhere, we submit an unprecedented opportunity to address this high-priority topic. We propose a large population-scale observational study to analyze routinely collected data from 2008 to 2018 from ~350,000 VLBW infants in more than 700 NICUs that are members of the California Perinatal Quality Care Collaborative or the Vermont Oxford Network. Together, these NICUs cover 85 percent of the VLBW infant birth hospitalizations in the US. Our analysis will use the Baby-MONITOR, a novel, valid and reliable composite measure of NICU quality developed by us in prior work, and its nine subcomponents, which together span quality of care delivery throughout the birth hospitalization. Our rationale for using the composite and its subcomponents is that comprehensive measurement will promote comprehensive improvement. This study is designed to achieve 3 specific aims: 1) Identify racial/ethnic differences and contributing factors in the quality of care provided within and between NICUs; 2) Identify racial/ethnic disparity profiles based on Baby-MONITOR sub-components within NICUs; and 3) Develop benchmarking reports of racial/ethnic disparity in quality of care delivery for NICUs. The datasets we will use afford more extensive opportunities to control for co-morbidities, social, and organizational risk factors than have been available in previous large-scale analyses of newborn outcome disparities, presenting the opportunity to study the role played by neighborhood level factors in VLBW quality of care delivery. Our work will focus on Black-White differences, disparities for Hispanics, and disparities for Asian and Pacific Islanders. As we conduct our analysis of disparities in NICU quality of care delivery, we will also advance the science of quality improvement by employing Bayesian longitudinal and prospective methodologies that allow NICU providers to assess and forecast disparities in care delivery.